Volunteers spread straw and hay around the nesting site for Stony Creek Metropark’s resident bald eagles. Volunteers and park officials are concerned the pair doesn’t have enough access to nesting materials this winter due to the deep snow pack. Photo courtesy of Sharon Sauriol

Stony Creek Metroparks’ resident bald eagles, which produced the first eagle offspring in the park’s history last year, are preparing to add some additional young this year, but the brutal winter conditions may prevent it from happening.

According to Stony Creek birding volunteers, the bald eagle pair was observed copulating on Sunday, Feb. 23. Typically, bald eagles then produce an egg, or eggs, about 4-5 days later. That means an egg(s) should have been in the nest by Thursday, Feb. 27. The nest, which is located in the northern end of the park property near Inwood Road, is estimated to be about 8-10 feet deep, about 4-5 feet deeper than last year, but is believed to have very little soft grasses at the top to line the nest.

From ground level, it is impossible to see whether or not the nest has enough grass lining. But Stony Creek volunteer bird expert Ruth Glass said observers have seen the eagle pair travelling further and further away from the nest looking for nesting materials without much success, since the deep snowpack is making access to grassland difficult. Some grasses are available in the wetlands around the nest area, but they may be too coarse or not insulating enough to use as nesting materials.

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“Last year, they’d get grass from inside the park in the adjacent wetlands and stream banks. But now you can barely see the top of the grass blades,” Glass said. “Now they are travelling out of the park and coming back with very little in their talons.”

In an attempt to help the bald eagles, Glass and other volunteers brought bales of hay and straw out to the nesting site Wednesday and spread them out on the ground, hoping the pair will utilize those materials to line the nest. Glass said similar tactics have been used successfully in Decorah, Iowa, as part of the Raptor Research Project. The Iowa bald eagles in their nest, can be seen via a 24-hour live stream.

Glass said the Stony Creek eagle pair is attempting to produce offspring one week earlier than last year, and is now potentially a victim to this year’s extreme winter conditions. With highs expected to remain below freezing, and lows in the single digits for the nest week, the egg(s) only need to be exposed to the elements for a short period of time to die. She called the egg’s chances of survival “quite slim.” Glass said bald eagles typically make only one attempt to produce offspring per breeding season. While observing the eagle pair on the Raptor Research Project live stream on Thursday with -2 degree temperatures in Decorah, Iowa, one adult got up from two eggs and flew away. The other adult immediately flew in and covered the eggs, leaving them exposed for no more than 20 seconds. But a second visit to the live stream showed adults off the nest for about seven minutes at a temperature of 0 degrees, before an adult returned, chewing on a meal.

Glass she is surprised the eagles actually remained in the park this winter. Bald eagles don’t migrate south in the way many bird species do, but they will go on the move if their food sources, fish in lakes and streams, freeze over.

Last year’s offspring, a female that is approaching its first birthday, has not been seen in the park since last fall. But there isn’t much concern about her welfare, since she probably left the park to establish her own territory. She was the first bald eagle to born in the park, established in 1964, and the first bald eagle to be born in that area in more than 100 years.

Charlie Shelton, a Stony Creek Nature Center interpreter, said a small patch of Stony Creek Lake, just below the North Dam, about 1,300 square feet, remained open until about mid-January. Since then, it has been frozen over more often than not, only providing access to the lake for short stretches during warmer, sunny days. He considers whatever fish the eagles are getting from that area a supplemental food source at best. He added the eagles will also eat carrion -- dead deer or other mammals -- plus small ducks and birds.

Glass said birders have reported a larger number of both adult and immature bald eagles on open patches of the St. Clair River this winter, since most other rivers and streams are ice covered. Even the Great Lakes are mostly frozen.

Last Wednesday, was the last day for park visitors to utilize the eastern part of the wetland loop, which allowed the closest legal access to the nesting site. The loop is now closed for the nesting season, which will last until September. Temporary signage has been posted warning visitors not to use the pathway, with fines and jail time possible for violators. Shelton said barricades will be erected within the next week.

Bald eagles require some distance from humans to function undisturbed. The Bald Eagle Protection Act remains fully enforced, with 220 yards, or 1/8 mile is the closest the U.S. Fish and Wildlife Service allows humans to approach a nesting site. Recommended viewing from the Michigan Department of Resources and the USFWS is 440 yards, or ¼ mile. Violators face a $5,000 fine and/or one year imprisonment.